Solar storms that led to dazzling auroras threatened to destroy thousands of satellites around Earth

Solar storms that led to dazzling auroras worldwide in May caused many satellites to lose altitude, putting them at risk of collision, a new study said.

The research, accepted for publication in the Journal of Spacecraft and Rockets , calls for a better understanding of the impact of solar storms on satellite operations and the sustainability of their orbits.

Spectacular northern lights dazzled across the skies of North America and Europe in May caused by one of the strongest-ever releases of charged particles from the Sun in centuries.

Auroras were surprisingly visible further south towards the equator reaching as far down as Ladakh in India and Alabama in the US.

However, due to a combination of poor forecasting and satellites needing to manoeuvre themselves back to their correct altitude “en masse”, the space weather event posed an unprecedented risk, researchers from Massachusetts Institute of Technology in the US said.

Currents induced by charged particles from the Sun during a solar storm are known to cause sudden satellite electronics failures in orbit.

For instance, during major solar storms in 1989 and 2003, America and Canada’s aerospace defence system Norad lost track of many of its satellites for several days.

As more commercial satellite constellations are launched today, most of which depend on automated collision avoidance systems, a similar failure “might have dire consequences”, researchers warned.

Estimates suggest that the number of active satellites in space has increased by eight-fold since 2003 and most of them sit in the Low Earth Orbit, which is relatively close to Earth’s surface.

Following the May 2024 solar storm activity, researchers found evidence that thousands of satellites in this orbit began to “manoeuvre en masse” in response to regain lost altitude.

Most of these satellites belong to the Starlink constellation which can perform autonomous orbit maintenance to quickly react to perturbing space events.

SpaceX said its satellites “weathered the geomagnetic storm and remain healthy” after the incident.

While there were no reported satellite collisions following the space weather event, scientists say transparency and open communication between operators is needed to avoid any risk in the future.

The May solar storm represented a “serious challenge” for the existing assessment of orbit infrastructure due to the large, unpredictable perturbations it caused on satellite trajectories, scientists say.

They call for a reconsideration of the robustness of current orbit assessment infrastructure to space weather events “when deciding how much to rely on it.”

“Moving forward, it is important that we recognize the limits that the environment imposes on satellite activity in LEO,” scientists wrote.